Opening device for flexible containers, container provided with such a device and application method thereof

ABSTRACT

An opening device for sealed flexible containers (1), comprising a label (5) having an adhesive face (6) intended to be adhesively applied to the inner face of a wall (3) of the container (1) and incorporating a substantially central longitudinal strip (7) having an initial portion (10) constituted by a gripper tongue (10). The wall (3) of the container (1) is formed with an aperture, either a hole (4) or a partial cut (24) delimiting on the container wall (3) a tearing wing (25), so as to allow the gripper tongue (10) of the label (5) to be pulled outwardly thus performing tear breakage of the label (5) and the consequent tearing of the wall (3) of the container (1).

TECHNICAL FIELD

The present invention is related to opening devices for flexiblecontainers, particularly packets or envelopes for bulk food products(even under vacuum or overpressure), as well as for powders, liquids andother solid materials.

These containers, sealed by the manufacturers, are opened for removal ofthe contents traditionally by cutting or tearing a top portion thereof,and cannot be subsequently again closed adequately so as to prevent orat least limit accidental coming out of the products.

BACKGROUND ART

U.S. Pat. No. 3,266,965 discloses an opening device for containers ofthe above-referenced type formed by a pair of walls sealed around therespective peripheral edges, comprising a tape element intended to beapplied to the inner face of one of said container walls andincorporating, along a substantially central area thereof, alongitudinal strip having a substantially initial portion defining agripper tongue, and wherein said one container wall is formed with anaperture for enabling said gripper tongue to be pulled outwardly so asto perform tear separation of said longitudinal tear strip relative tosaid tape element and consequent tearing of said one container wall.

According to this known construction, which is specifically directed tocontainers at least in part made of thermoplastic sheet material, thetape element is a composite layered material having an inner core andtwo outer covering layers made of a thermoplastic material which is sameas or compatible with the thermoplastic material of the container. Thistape element is applied to the inner face of the container wall by meansof heat and pressure, e.g. by heat welding.

The main drawback of this known solution resides in the complicated andthus expensive construction of the tape element, as well as in the limitthat same can only be used in association with containers at leastpartially made of thermoplastic material.

On the other hand, the aperture of the container wall through which thegripper tongue is accessible from the outside is placed in the immediateproximity of one edge of the container wall and, consequently, thesealed region of the container walls is necessarily formed--so as toensure airtight closure of the container before opening thereof--with aninwardly recessed region astride the tape element.

A further drawback of this known construction resides in the relativelydifficult and thus expensive manufacturing of the container providedwith the opening device, in connection with heat-pressure welded sealedconnection both of the device onto the corresponding container wall, andbetween the two container walls.

Pull strip opening arrangements for containers are also generally knownfrom U.S. Pat. No. 4,773,541 and U.S. Pat. No. 4,328,924 and fromGB-A-2,172,545.

DISCLOSURE OF THE INVENTION

The object of the present invention is to overcome the above drawbacksand to provide a simple and cheap opening device, which is adapted to beapplied to containers made of any kind of material, i.e. not necessarilyof thermoplastic material, and which enables both to open the first timethe container in a convenient and practical way, and to provideimmediate visual indication of any prior opening of the container.

A further object of the invention is to provide an opening device whichis adapted to be applied onto the container in a simple and mechanizedway.

Another object of the invention is to provide an opening device withoutany limitations in connection with the material both of the deviceitself and of the container to which the device is intended to beassociated, and also not requiring heat welding techniques for theapplication thereof.

Still a further object of the invention is to ensure, in the appliedcondition of the opening device, a total hermetic seal of the containerso as to preserve any underpressure or overpressure formed therein.

The device according to the invention is primarily characterized in thatsaid tape element is a label having an adhesive face adhesively securedto said inner face of said one container wall, and in that said aperturefor the gripper tongue of the longitudinal tear strip of the label isformed in an inner area of said one wall with respect to said sealedperipheral edges of the container walls.

In the following specification and claims the term "longitudinal strip"of the label is to be intended as referred both to a small web or stringwhich is distinct from the label and is applied over one face thereof,or even to an integral portion of the label defined between two parallelseries of adjacent pre-cut segments.

The label has conveniently an elongated shape and preferably thelongitudinal strip is extending substantially along the entire length ofthe label. The longitudinal strip may be applied either on one or on theother face of the label, but preferably on the face opposite to theadhesive one, i.e. on the face which is not in contact with thecontainer wall. In this case, the gripper tongue may be convenientlydefined by a cut of the label formed astride of the longitudinal strip.This cut is substantially U-shaped, and is conveniently placed at apredetermined distance from one end of the label.

According to a first embodiment of the invention, said aperture of thecontainer wall is formed by a complete hole through which the grippertongue is fitted and projects outwardly, in an accessible way fromoutside the container.

According to another embodiment of the invention, which is presently tobe considered as the preferred one, the aperture of the container wallis constituted by a partial cut which is separated, through anon-pierced area of the container wall, from said cut delimiting thegripper tongue of the label.

In this case the partial cut, which is also placed astride of thelongitudinal strip of the label, defines on the container wall a tearwing against which the gripper tongue of the label adheres. In thisembodiment, when the tear wing is pulled outwardly, breakage of saidunimpaired area of the container wall is accomplished and, consequently,entrainment of the gripper tongue occurs thus producing tear breakage ofthe label and consequent tearing of the container wall.

This solution is adapted to ensure, in the applied condition of theopening device, a perfect hermetic seal of the container, since anycommunication between the interior thereof and the outer environment isexcluded. In the case of the first embodiment, wherein the aperture ofthe container wall is constituted by a complete hole, to the aim ofensuring hermetic seal of the container the invention contemplates anair-tight wall applied in correspondence of the U-shaped cut of thelabel and having a central area which is made non-adhesive and isarranged in correspondence of the gripper tongue of the longitudinalstrip.

The longitudinal strip may also be applied only onto a portion of thelabel, in the area which is intended to define the tearing line. Theportions of the label comprised between the two ends thereof thus act asreinforcement elements of the container wall, so as to efficientlyprevent undesired breakage or tearing thereof beyond the predeterminedlimits.

In case the longitudinal strip is applied between the container wall andthe wall of the label, the previous U-shaped cut may be simplified as acut over the strip without cutting also the label wall. Air-tightness ofthe package shall be ensured in this case by the integrity without anycuts of the label wall and, therefore, application of an air-tight wallis no more necessary. Opening of the label wall simultaneously withtearing of the container wall may be pre-arranged by means of a pre-cutline or through a pre-punching of an area of the label which shall beremoved by pulling the gripper tongue.

According to a further aspect of the invention, the opening device alsocomprises an adhesive portion which is associated laterally andparallelly to the longitudinal strip of the label and is intended to bepositioned on the outer surface of said container wall following thefirst opening thereof.

This adhesive wall, the function of which is to enable reclosing of thecontainer by simply folding the end edge thereof against said outersurface, may be formed by an area of the adhesive face itself of thelabel, or by an additional bi-adhesive label or by a simple piece ofadhesive tape.

The invention is also related to a container provided with an openingand reclosing device such as set forth in the above, as well as to amethod for application of the device itself.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be disclosed in detail with reference to theaccompanying drawings, purely provided by way of non-limiting example,in which:

FIG. 1 is a diagrammatic and partial perspective view of a flexiblecontainer provided with an opening device according to a firstembodiment of the invention,

FIG. 2 is a plan view showing the adhesive label employed in the openingdevice of FIG. 1,

FIG. 3 shows an alternative embodiment of FIG. 2,

FIG. 4 is a diagrammatic longitudinal section taken along line IV--IV ofFIG. 1,

FIG. 5 is a perspective exploded view of the device of FIG. 1,

FIG. 6 is a perspective view depicting the container during openingthereof,

FIG. 7 shows a further alternative embodiment of FIG. 2,

FIG. 8 is a diagrammatic section similar to FIG. 4 according to thealternative embodiment of FIG. 7,

FIG. 9 depicts the container of FIG. 1 provided with a reclosing device,

FIG. 10 shows a first alternative embodiment of the reclosing device,

FIG. 11 shows the opened condition of the device according to FIG. 10,

FIG. 12 shows the condition of reclosure of the container with thedevice according to FIGS. 10 and 11,

FIGS. 13 and 14 show two further respective alternative embodiments ofthe reclosing device,

FIG. 15 is an exploded perspective view, similar to FIG. 5, showing afurther embodiment of the device according to the invention, which ispresently to be considered as the preferred embodiment thereof, and

FIG. 16 is a diagrammatic top plan view of the device according to FIG.15.

PREFERRED EMBODIMENTS OF THE INVENTION

Referring initially to FIGS. 1 through 5, reference numeral 1 generallydesignates a flexible container, for instance constituted by a sealedpacket normally made of paper, thermoplastic material, plasticized paperor any other suitable material, which is intended to contain bulk foodproducts, even under vacuum or overpressure.

The container 1 is formed by two walls 3, 3a sealingly connected to eachother laterally and along one end 2 of the container 1, by means of heatwelding or glueing.

The wall 3 is formed with a hole 4, normally having a circular shape,situated in correspondence of a lateral area at a certain distance fromthe end 2 and closer to one side edge of the container 1 than to theother side edge. A breakage-guiding slot 4a departing from the hole 4may be provided.

A label 5 having an elongated rectangular shape and provided with anadhesive, preferably self-adhesive face 6, is applied onto the innerface of the wall 3, at the same level of the hole 4.

The label 5 is preferably made of paper or thermoplastic material andthe like.

As it can be better seen in FIG. 2, the label 5 incorporates along asubstantially central area thereof a longitudinal strip 7 which, in thecase of the shown embodiment, is constituted by a narrow web, forinstance made of plastic material, which is adherent to the outer faceof the label, i.e. the face which is not in contact with the wall 3 ofthe container 1. As an alternative, the strip 7 may be constituted by astring or wire applied over the inner face of the label, or by a portionof the label 5 itself delimited between two series of adjacentpre-punched segments directly formed across the label.

In the embodiment shown in FIG. 2, the strip 7 is extending over theentire length of the label 5. Reference numeral 8 designates a U-shapedcut formed astride of the strip 7 at a predetermined distance from oneend of the label 5. The cut 8 is made across both the label 5 and thestrip 7. In correspondence of the other end of the label 5 a second cut9 is formed through the wall of the label 5 and the strip 7. Alongitudinal pre-cut or pre-punched line 9a (FIG. 2) may possibly beformed in the wall of the label 5, spanning between the cuts 8 and 9 tothe aim of facilitating breakage of the wall of the label 5 along thestrip 7.

The end of the strip 7 corresponding to the cut 8 is bent outwardly andis arranged through the hole 4 of the wall 3, so as to define a grippertongue 10 projecting outside of the container 1 (FIG. 4).

In the alternative embodiment shown in FIG. 3, the longitudinal strip 7is applied only onto a portion of the label 5, in correspondence of thearea which is intended to define the tearing line. In this case, the cut8 is only affecting the wall of the label 5 and it is not necessary toprovide the second cut 9. Even in this case a longitudinal pre-cut linemay be contemplated.

Referring to FIGS. 4 and 5, reference numeral 11 indicates an adhesiveair-tight wall, defined by a second label whose length is appreciableshorter than that of the label 5, and which is applied onto one facethereof in the area corresponding to the hole 4. The air-tight wall 11has an area 12 which is made non-adhesive and is arranged incorrespondence of the cut 8, i.e. of the gripper tongue 10.

The air-tight wall 11 may possibly be applied outside, over the hole 4and the gripper tongue 10.

FIGS. 7 and 8 depict a second embodiment of the label which may beemployed in the device according to the invention. In this secondembodiment the strip 7 is applied on the adhesive face 6 of the label 5and in use it is arranged between the wall 3 of the container 1 and thelabel 5. In this case two cuts 8a, 8b may be provided, only affectingthe wall of the strip 7 without piercing the label wall. Air-tight sealof the packet shall be ensured by the integrity of the wall of the label5 across which no cuts are provided. In this case application of anair-tight wall is thus unnecessary. In the area of the cut 8a, the wall5 is provided with a portion 10a which is made non-adhesive and incorrespondence of which the strip 7 is detached from the label 5 anddirectly forms the gripper tongue 10.

Opening of the wall of the label 5 simultaneously to tearing of the wall3 of the container 1 may also be obtained by virtue of a pre-cut orpre-punching line of an area 5a of the label 5 which shall be removedwhen pulling the gripper tongue 10.

Normally the container 1 is formed starting from a continuous sheet,wound on a reel, which is then severed according to the desired size,folded and heat welded along the lateral edges, then filled with theproducts and lastly sealed along the end 2.

Application of the opening device according to the invention isperformed on the continuous sheet forming the holes 4 at predetermineddistances and any punchings for possibly delimiting areas to betear-removed, and then positioning and adhering the respective labels 5such as previously disclosed. In case of tear-web 7 is arranged outsideof the label, the second labels 11 will then be applied, according towhat has been previously clarified.

Following filling in, the container 1 is then sealed by means of heatwelding or equivalent systems along the end 2 thereof.

To perform opening of the container 1, it is sufficient to grasp thegripper tongue 10 which projects across the hole 4 and pull this tongueoutwardly, which causes tear-separation of the strip 7 from the label 5and, consequently, tearing of the wall 3 such as depicted in FIG. 6,simultaneously with tearing of the label 5 such as previously disclosed.In this way an opening 13 is generated along the wall 3, extending fromthe gripper tongue 10 of the strip 7 as far as the second cut 9, ifpresent, thereof, or as far as its opposite end, whereby the strip 7 iscompletely separated from the label 5.

The opening 13 enables convenient withdrawal of the contents from thepacket, and the lateral and longitudinal end portions of the label 5which remain adherent to the inner surface of the wall 3 effectivelyprevent breakage thereof beyond the limits of the initial tearing.

The invention contemplates four alternative embodiments of the deviceintended to permit subsequent reclosing of the container 1 by foldingthe end 2 thereof above the opening 13, so as to prevent accidentaloutlet therefrom of the contents.

The first variant, shown in FIG. 9, is employing a supplementarybi-adhesive label 14 having one face applied outside of the wall 3,laterally of the strip 7 of the label 5, and on the opposite face ofwhich a peelable protection 15 is applied. Following opening of thecontainer 1, such as previously disclosed, the protection 15 is removedand the end 2 can than be folded and adhered through the auxiliary label14 against the wall 3, beyond the opening 13.

The second variant, depicted in FIGS. 10, 11 and 12, contemplates theformation on the wall 3 of a pre-cut 16 punched in the area ofapplication of the label 5, i.e. above the latter, laterally andparallelly to the strip 7. The pre-cut 16 actually is bordering on thearea of the wall 3 along which the strip 16 extends, and has an initialsection 16a and a final section 16b which are respectively diverging andconverging with respect to that area, so as to define a means forfacilitating removal.

The cut 16 in practical terms is delimiting a wing 17 which, upontearing of the strip 7 of the label 5, i.e. upon formation of theaperture 13, is removed together with the strip 16 thus exposing acorresponding portion 6a of the adhesive face 6 of the label 5 (FIG.11). The portion 6a can then be used for reclosing the container 1, byadhering thereagainst the wall 3 beyond the opening 13, after foldingthe end 2 of the container 1 over such opening in the way shown in FIG.12.

The third variant, depicted in FIG. 13, can be applied in the embodimentaccording to FIGS. 7 and 8, i.e. in case the strip 7 is arranged betweenthe wall 3 of the container and the label 5. This variant provides theuse of a strip 7 having a substantial width which, upon removal thereofand trailing therewith a corresponding portion 7a of the wall of thecontainer 1, exposes an adhesive portion 6b of the label 5.

The fourth variant shown in FIG. 14 contemplates the use of a simpleadhesive tape 18 which is applied on the container wall and is providedwith a releasable protection member.

It is evident that the method for applying the device to the continuoussheet employed for the subsequent formation of the container 1 shallcontemplate in the case of the first variant the application of theauxiliary labels 14, and in the case of the second embodiment theformation of the cuts 16.

In the case of the third variant it will be necessary to employ strips 7having a greater width, and in the case of the fourth variant it will benecessary to provide application of the adhesive tape 18 onto thecontainer wall.

FIGS. 15 and 16 diagrammatically show a further alternative embodimentof the opening device according to the invention, which is presentlyconsidered as the preferred embodiment.

This variant differs from the previously disclosed embodimentessentially in that the complete hole 4 on the wall 3 of the container 1is replaced by a partial cut of this wall 3, having for instance theshape depicted at 24 in FIGS. 15 and 16. The partial cut 24 is formedastride of the longitudinal strip 7 of the label 5 and delimits on thewall 3 a tear wing 25. As it can be better seen in FIG. 16, the partialcut 24 is arranged in such a way that the tear wing 25 is separated fromthe cut 8 defining the gripper tongue 10 of the label 5, throughunpierced areas of the wall 3. The partial cut 24 is conveniently formedso as to be provided with end sections converging towards the cut 8(such as shown in the figures), or even so as to be placed astridethereof. In any case it is necessary that no communication existsbetween the cut 8 and the partial cut 24.

Reference 26 designates a portion made non adhesive of the adhesive face6 of the label 5, across the central area thereof corresponding to thestrip 7, and placed in correspondence at least of an initial portion ofthe tear wing 25, so as to allow convenient grasp thereof from outsideof the container 3.

Even in this case the container 1 is formed starting from a continuoussheet, wound on a reel, which is then size-cut, folded and heat weldedalong its sides, then filled in with the products and lastly sealed asin the case of the embodiments disclosed in the above.

Application of the opening device on the continuous sheet is performedin this case punching the partial cuts 24 at predetermined distances,and then positioning and adhering the respective labels 5 with thecorresponding cuts 8 and the corresponding non-adhesive portion 26arranged in the way previously explained.

Following filling in and sealing of the container 1, the absence of anycommunication to the exterior through the opening device ensures a totalhermetic seal.

In order to open the container 1 it is sufficient in this case to graspthe tear wing 25 in correspondence of the non-adhesive portion 26 of thelabel 5, and pull this tear wing 25 outwardly, thus causing breakage ofthe areas of the wall 3 comprised between the partial cut 24 and the cut8 and, consequently, "capture" of the gripper tongue 10 and consequenttear removal of the strip 7, thus performing tearing of the wall 3,correspondingly to what is shown in FIG. 6 with reference to the firstembodiment.

The various embodiments of the reclosing device of the container 1,previously disclosed with reference to FIGS. 9 through 14, can also beemployed in the embodiment of FIGS. 15 and 16.

Naturally the details of construction and the embodiments of the devicemay be widely varied with respect to what has been disclosed andillustrated, without thereby departing from the scope of the presentinvention such as defined in the appended claims.

I claim:
 1. An opening device for flexible sealed containers formed by apair of walls sealed around respective peripheral edges, said openingdevice comprising a tape element adapted to be applied to the inner faceof one of said container walls and incorporating along a substantiallycentral area thereof, a longitudinal strip having a substantiallyinitial portion defining a gripper tongue, wherein said gripper tongueis adapted to be pulled outwardly through an aperture in said onecontainer wall so as to perform tear separation of said tape element bysaid longitudinal tear strip and to tear said one container wall,wherein said tape element is a label having an adhesive face adapted tobe adhesively secured to said inner face of said one container wall andsaid gripper tongue of said longitudinal tear strip of said label isadapted to be located in an inner area of said one wall with respect tosaid sealed peripheral edges of the container walls, wherein the grippertongue of the label is defined by a cut of the label, wherein thegripper tongue of the label is adapted to adhere to a tear wing of saidwall of the container, which tear wing is delimited by a partial cutadapted to be separated, through non-pierced areas of said wall of thecontainer, from said cut delimiting the gripper tongue of the label,wherein said longitudinal strip of the label is adapted to extend acrosssaid partial cut and wherein the adhesive face of the label has anon-adhesive portion adapted to be arranged in correspondence with atleast one initial portion of the tear wing of said wall of thecontainer.
 2. A device according to claim 1 wherein the label has anelongated shape and said longitudinal strip extends substantially alongthe entire length of the label and wherein said gripper tongue isdefined by a substantially U-shaped cut formed astride of said strip ata predetermined distance from one end of the label.
 3. A deviceaccording to claim 1 wherein the label has an elongated shape and saidlongitudinal strip extends along a length which is shorter than thelength of the label and wherein the gripper tongue is defined by aU-shaped cut formed in the wall of the label adjacent to one end of thestrip.
 4. A device according to claim 1 wherein said strip is applied onthe face of the label opposite to said adhesive face.
 5. A deviceaccording to claim 1 wherein said strip is applied on the adhesive faceof the label and wherein said gripper tongue is defined incorrespondence with a non-adhesive portion of the adhesive face of thelabel.
 6. A device according to claim 1 wherein the label has a secondcut opposite to said first mention cut and formed astride of thelongitudinal strip at a predetermined distance from the other end of thelabel.
 7. A device according to claim 1 further comprising an adhesivemember laterally associated with said longitudinal strip of the labeland adapted to be positioned on the outer surface of the said wall ofthe container.
 8. A device according to claim 7 wherein said adhesivemember is an area of the adhesive face of the label.
 9. A deviceaccording to claim 7 wherein said adhesive member is defined by anauxiliary bi-adhesive label.
 10. An opening device for flexible sealedcontainers formed by a pair of walls sealed around the respectiveperipheral edges, said opening device comprising a tape element adaptedto be applied to the inner face of one of said container walls andincorporating, along a substantially central area thereof, alongitudinal strip having a substantially initial portion defining agripper tongue, wherein said gripper tongue is adapted to be pulledoutwardly through an aperture in said one container wall so as toperform tear separation of said tape element by said longitudinal tearstrip and to tear said one container wall, wherein said tape element isa label having an adhesive face adapted to be adhesively secured to saidinner face of said one container wall and said gripper tongue of saidlongitudinal tear strip of said label is adapted to be located in aninner area of said one wall with respect to said sealed peripheral edgesof the container walls, wherein the gripper tongue of the label isdefined by a cut of the label and further comprising an adhesiveair-tight wall defined by a second label applied in correspondence withthe cut of said label, said second label having a non-adhesive centralarea placed in correspondence with the gripper tongue of thelongitudinal strip.
 11. A device according to claim 11 wherein thesecond label is applied on the face of said label opposite to therespective adhesive face.
 12. A sealed flexible container formed by apair of walls sealed around the respective peripheral edges, saidcontainer having an opening device comprising a tape element applied toan inner face of one of said container walls and incorporating, along asubstantially central area thereof, a longitudinal strip having asubstantially initial portion defining a gripper tongue, wherein saidone container wall is formed with an aperture for enabling said grippertongue to be pulled outwardly so as to perform tear separation of saidtape element by said longitudinal tear strip and to tear said onecontainer wall, wherein said tape element is a label having an adhesiveface adhesively secured to said inner face of said one container walland said aperture is formed in an inner area of said one wall spacedfrom said sealed peripheral edges of the container walls, wherein thegripper tongue 10 of the label is defined by a cut of the label, whereinthe gripper tongue of the label adheres to a tear wing of said wall ofthe container, which tear wing is delimited by a partial cut separatedfrom said first mention cut delimiting the gripper tongue of the label,wherein said partial cut is arranged astride of the longitudinal stripof the label and wherein the adhesive face of the label has anonadhesive portion adapted to be arranged in correspondence with atleast one initial portion of the tear wing of said wall of thecontainer.
 13. A sealed flexible container formed by a pair of wallssealed around the respective peripheral edges, said container having anopening device comprising a tape element applied to the inner face ofone of said container walls and incorporating, along a substantiallycentral area thereof, a longitudinal strip having a substantiallyinitial portion defining a gripper tongue, wherein said one containerwall is formed with an aperture for enabling said gripper tongue to bepulled outwardly so as to perform tear separation of said tape elementby said longitudinal tear strip and to tear said one container wall,wherein said tape element is a label having an adhesive face adhesivelysecured to said inner face of said one container wall and said thegripper tongue of said longitudinal tear strip being formed in an innerarea of said one wall in spaced relation to said sealed peripheral edgesof the container walls, wherein the gripper tongue of the label isdefined by a cut of the label and further comprising an adhesiveair-tight wall defined by a second label applied in correspondence ofthe cut of said label, said second label having a nonadhesive centralportion place in correspondence with the gripper tongue of thelongitudinal strip.
 14. A sealed flexible container as set forth inclaim 13 wherein the second label is applied on the face of said labelopposite to the respective adhesive face.